comparison armadillo-2.4.4/include/armadillo_bits/glue_conv_meat.hpp @ 0:8b6102e2a9b0

Armadillo Library

+// Copyright (C) 2010-2011 NICTA (www.nicta.com.au)
+// Copyright (C) 2010-2011 Conrad Sanderson
+// 
+// This file is part of the Armadillo C++ library.
+// It is provided without any warranty of fitness
+// for any purpose. You can redistribute this file
+// and/or modify it under the terms of the GNU
+// Lesser General Public License (LGPL) as published
+// by the Free Software Foundation, either version 3
+// of the License or (at your option) any later version.
+// (see http://www.opensource.org/licenses for more info)
+
+
+//! \addtogroup glue_conv
+//! @{
+
+
+//! rudimentary implementation of the convolution operation
+
+template<typename T1, typename T2>
+inline
+void
+glue_conv::apply(Mat<typename T1::elem_type>& out, const Glue<T1,T2,glue_conv>& X)
+  {
+  arma_extra_debug_sigprint();
+  
+  typedef typename T1::elem_type eT;
+  
+  const unwrap_check<T1> A_tmp(X.A, out);
+  const unwrap_check<T2> B_tmp(X.B, out);
+  
+  const Mat<eT>& A = A_tmp.M;
+  const Mat<eT>& B = B_tmp.M;
+  
+  arma_debug_check( ( (A.is_vec() == false) || (B.is_vec() == false) ), "conv(): inputs must be vectors" );
+  
+  
+  const Mat<eT>& h = (A.n_elem <= B.n_elem) ? A : B;
+  const Mat<eT>& x = (A.n_elem <= B.n_elem) ? B : A;
+  
+  
+  const uword   h_n_elem = h.n_elem;
+  const uword   x_n_elem = x.n_elem;
+  const uword out_n_elem = h_n_elem + x_n_elem - 1;
+  
+  
+  if( (h_n_elem == 0) || (x_n_elem == 0) )
+    {
+    out.reset();
+    return;
+    }
+  
+  
+  (A.n_cols == 1) ? out.set_size(out_n_elem, 1) : out.set_size(1, out_n_elem);
+  
+  
+  const eT*   h_mem = h.memptr();
+  const eT*   x_mem = x.memptr();
+        eT* out_mem = out.memptr();
+  
+  
+  for(uword out_i = 0; out_i < (h_n_elem-1); ++out_i)
+    {
+    eT acc = eT(0);
+    
+    uword h_i = out_i;
+    
+    for(uword x_i = 0; x_i <= out_i; ++x_i, --h_i)
+      {
+      acc += h_mem[h_i] * x_mem[x_i];
+      }
+    
+    out_mem[out_i] = acc;
+    }
+  
+  
+  for(uword out_i = h_n_elem-1; out_i < out_n_elem - (h_n_elem-1); ++out_i)
+    {
+    eT acc = eT(0);
+   
+    uword h_i = h_n_elem - 1;
+    
+    for(uword x_i = out_i - h_n_elem + 1; x_i <= out_i; ++x_i, --h_i)
+      {
+      acc += h_mem[h_i] * x_mem[x_i];
+      }
+      
+    out_mem[out_i] = acc;
+    }
+  
+  
+  for(uword out_i = out_n_elem - (h_n_elem-1); out_i < out_n_elem; ++out_i)
+    {
+    eT acc = eT(0);
+    
+    uword h_i = h_n_elem - 1;
+    
+    for(uword x_i = out_i - h_n_elem + 1; x_i < x_n_elem; ++x_i, --h_i)
+      {
+      acc += h_mem[h_i] * x_mem[x_i];
+      }
+    
+    out_mem[out_i] = acc;
+    }
+  
+  
+  }
+
+
+
+//! @}